Island



' (No Model.)

F. H. MANCHESTER. INGANDESGENT LAMP.

No. 469,483. Patented Feb.'23, 1892.

WITNESS-E5: INS/INTER 54%{522Zt 7' 94/ W UNITED STATES PATENT OFFICE.

FREDERIC H. MANCHESTER, OF PROVIDENCE, RIIODE ISLAND.

INCANDESCENT LAMP.

SPECIFICATION forming part of Letters Patent No. 469,483, dated February23, 1892. Application filed November 4, 1891. Serial No. 410,821. (Nomodel.)

To aZZ whom it may concern:

Be it known that I, FREDERIO H. MANOHES: TER, of the city of Providence,in the county of Providence and State of Rhode Island, have inventedcertain new and useful Improvements in Incandescent Lamps; and I herebydeclare that the following is a full, clear, and exact description ofthe same, reference being had to the accompanying drawings, forming partof this specification.

This invention has reference more especially to improvements in thebases in which the glass bulbs of the lamps are permanently secured andwhich are adapted to be secured in lamp-sockets having a centralcontactpost and a circumferential contact-plate.

The object of this invention is to produce a base for incandescent lampswhich will be more durable than those heretofore manufactured and reducethe cost of the same. To attain these ends, I have invented a lampbaseprovided with an insulating plate formed of porcelain, together withcertain novel features of construction and peculiar combination ofparts, which will hereinafter be more particularly described, andpointed out in the claim.

Figure 1 represents the improved base secured to the bulb of anincandescent lamp. Fig. 2 represents a top view of the base. Fig. 3represents a vertical sectional view of the base, taken at a line a, b,Fig. 2, showing the manner in which parts of the base are securedtogether and connected with the lampwires.

Similar numbers of reference designate corresponding parts throughout.

In the drawings, 5 indicates the shell of the base. This shell is spunup from sheet metal and has the corrugations 6 pressed. from thethickness of the metal and forming a screwthread, by which the base andthe bulb held therein are secured in the lamp-socket. The lip 7 isprovided at the upper portion of this shell and is bent over the thinedge of the insulating-plate to secure the same to the shell. Theinsulating-plate 8 is formed of porcelain and is circular in shape,having a thin edge 9,-over which the lip 7 of the shell is bent, and acentral boss 10, which is perforated vertically, the perforationextending through the thickness of the insulating-plate into the cavity11 in the under side thereof.

A side perforation 12 is also formed through the thinner portion of theplate 8. The perforated cap 13 fits closely around the edges of the boss10 and is secured in place by the tube 14, the flange 15 of which fitsinto the cavity 11, while the upper end extends through the perforationof the cap 13, over the edges of which it is expanded, drawing the uppersurface of this cap downward and forming a slight concaved recess. Thelampvvire 16 extends through the perforation 12 and is secured,preferably by solder, to the cap 13, while the wire 17 is secured to themetal shell 5, these wires being connected to the filament of the lamp.hen this base is secured to a screwsocket, the shell 5 is connected withthe inner shell of the socket and thence to one pole of the electriccircuit, and the upper edge of the tube 14 is forced into contact with apin or plate connected with the other pole of the electric circuit. Theporcelain insulating plate 8 can be made smaller and less cumbersomethan when made of Wood and may be more securely fastened.

to the shell 5 bysimply spinning the lip 7 over the thin edge of theplate, as this plate can be molded complete in shape, and with theperforations formed therein the cost of manufacture is greatly reduced.At-the same time an insulating-plate is formed which will not becomeloose from shrinkage and which will not retain sufiicient moisture tooccasion a short circuit of the electric current.

Having thus described my invention, 1 claim as new and desire to secureby Letters Patent In an incandescent lamp, the combination, with thebase 5, having the corrugations 6 and lip 7, of the porcelaininsulating-plate 8, secured within said lip and having a sideperforation 12 and a central perforated boss 10, a metal cap 13,covering said boss and secured in place by the flanged tube 14,extending through said perforation, and wires adapted to connect saidshell 5 and cap 13 with the lamp-filament, as described.

In witness whereof I have hereunto set my hand.

FREDERIC H. MANCHESTER.

Witnesses:

HENRY J. MILLER, M. F. BLIGH.

